Avaliação da área valvar aórtica combinando ecocardiografia e ressonância magnética

Abstract

Background: Transthoracic echocardiography (TTE) is routinely used to calculate aortic valve area (AVA) by continuity equation (CE). However, accurate measurement of the left ventricular outflow tract (LVOT) can be difficult and flow acceleration in the LVOT may lead to miscalculation of the AVA.

Aliased Flow Signal Planimetry by Cardiovascular Magnetic Resonance Imaging for Grading Aortic Stenosis Severity: A Prospective Pilot Study

“…As mentioned earlier, accuracy in quantifying AS could be improved by the use of a multimodality metric, EOA hybrid , combining strengths and avoiding the pitfalls of both TTE and CMR. The continuity equation can be obtained by using LVOT area derived from CMR and velocities measured by Doppler TTE (11)(12)(13)(14)(15). Although conceptually attractive, this approach is cumbersome and not easily applicable in clinical routine, as it would require a costly sequential acquisition of two different diagnostic tests possibly under the same hemodynamic conditions.…”

“…A hybrid approach, in which LVOT area is measured by CMR and the LVOT and aortic velocities are determined using Doppler echocardiography (EOA hybrid ) (11)(12)(13)(14), should overcome the methodological limitations of 2D echocardiography for measurement of LVOT area and of CMR for measurement of velocities and GOA. However, the hybrid approach is timeconsuming, not widely available and expensive, but it represents a non-invasive alternative, potentially useful in patients in whom echocardiographic results are inconclusive or conflicting.…”

A New Method for Aortic Valve Planimetry with High-Resolution 3-Dimensional MRI and Its Comparison with Conventional Cine MRI and Echocardiography for Assessing the Severity of Aortic Valvular Stenosis

“…The severity of aortic valvular stenosis (AS) can be assessed with Doppler echocardiography by measuring the AS jet velocity, and the aortic valve area (AVA) can be assessed by either the continuity equation or direct planimetry [ 1 2 3 4 5 ]. Doppler echocardiography does not provide direct information on pressure; instead, it relies on the measurement of the left ventricular outflow tract (LVOT).…”

“…More recently, cardiovascular magnetic resonance (CMR) has emerged as a complementary tool for noninvasively evaluating AS [ 2 7 8 9 10 11 12 13 ]. Studies have shown its usefulness for the assessment of AVA and aortic hemodynamic parameters, either by planimetry of cine anatomical images or by analyzing velocity-encoded images using the continuity equation [ 14 15 ].…”

Contribuição da ressonância magnética cardíaca (mapa T1) e ecocardiograma tridimensional para avaliação da reserva contrátil em pacientes com estenose aórtica importante com gradiente baixo e fração de ejeção reduzida

“…A imagem de realce tardio foi realizada 20 minutos após a infusão de bolus de gadolinio-DTPA na dose de 0,1 mmol/kg com a utilização de bomba injetora, através de acesso venoso periférico. As sequências de pulsos foram sincronizadas ao eletrocardiograma, visando a aumentar as taxas de sinal-ruído e melhorar a qualidade das imagens.As medidas de T1 foram realizadas antes da injeção de contraste e 5, 10, 15, 20 e 30 minutos após injeção do contraste paramagnético, utilizando protocolo de sequência de inversão Look Locker modificada (da sigla em inglês MOLLI) sincronizada ao eletrocardiograma, previamente descrita35 . Como alguns pacientes apresentavam áreas de realce tardio, realizamos análises incluindo e excluindo todas as áreas de fibrose focal.…”